Stop mechanism for presses



Jan. 31, 1928. 1,657,499

J. DERRY 4 STOP MECHANISM FOR PRESSES F iled Oct. 20. 1924 2Sheets-Sheet 1 I A III All. W

by MQLA\&N\ ATT YE- Jan. 31, 1928. 1,657,499

J. DERRY STOP MECHANISM FOR PRESSES Fild on. 20,1924 2 Sheets-Sheet 2 NNT 'V y JZWQQ wflw lkwifld.

A T RP' Y? Patented Jan. 31, 1928.

UNITED STA;

1,657,499 PATENT OFFIQEZ.

Jasmin DER-B12026 "ivrnnronn, ranssecnnsn'rrs, AGSIGNOR To annnnwrnmrntsnn, on nos'ron, nmssacrrnsnr rs.

STOP MECi-EANISM FOR PRESSE S.

Application filed October 20, 1924. Serial No. 744,862.

This invention relates to mechanically operated power presses. and hasfor its object to provide simple and effective mechanism torauton'iatically stopping the press when the ram or movable press elementreaches the limit of its movement away from or toward the bed orstationary element, in the one case to permit the ready insertion andremoval of the work, and in the other to hold the work under pressure,and for permitting the press to be manually started after having beenautomatically stopped in either position.

The more particular objects of the invention together witlrmeans wherebythe latter may be carried into eflect, will best be understood from thefollowingdescription of one term or embodiment thereof illustrated inthe accompanying drawings. It will be understood, however. that theparticular construction described and shown hasbeen chosen forillustrative purposes merely, and that the invention, as defined by theclaims hereui'ito appended, may be otherwise practised without departingfrom the spirit and scope thereof.

In said drawings:

Fig. l is a plan View of a press having stop mechanism en'ibodying theinvention.

Fig. 2 is a sect-ion taken substantially on the line 2-2, Fig. 1.

Fig. 8is a section taken substantially on the line 83, Fig. 1, butshowing the parts in a slightly different position to illustrate theoperation of the stop mechanism.

Fig. & is a detail section takensubstair tially on the line it-14, Fig.3. y

The frame of the press, as shown. comprises a pair of side uprights 10having shoulders 11 upon which are supported the lower ends of fourupright rods or posts 12, said posts above their lower endsbeingreceived and held in spaced upright position by hollow bosses 19formed on the upper ends of the uprights. Adjacent their lower ends theposts 12 are threaded, as shownat 13, to receive nuts 1 1 by which isadjustably supported a bed plate 15, carrying the bed 16 or stationaryelement of the press. The rain 17, or cooperating movable element of thepress, is formed with hollow bosses 18 which are guided upon theposts12. The

ram l'iis moved toward and from the "bed' 16 by means of a toggle20'interposedjbetween said rain and a crosshead2l carried by the posts12. is herein shown, the crosshead 21 is slidably mounted on said postsand is normally held in engagement with nuts 22 on the latter by meansof springs 23 interposed between said cross-head and nuts 2st on theupper ends of said posts, for the purpose more fully explained in aprior ap 'plication filed February 18, 1924, Serial No.

on a cam fast on the shatt 29, said cam operating to reciprocate thelink 26 to nternately straighten and break the toggle.

Journalled in the uprights 10 is a trans verse main shaft 33 disposedsubstantially parallel to the cam shaft 29 and adapted to be rotatedtrom any suitable source of power,

not sho wn. Fast on the shaft is a pinion 8% (Fig. which meshes with agear 35 fast on a countershatt 36, also journalled in the uprights 10and disposed parallel to the main shaft 33. The countershaft 36 hassplined thereto, for movement longitudinally thereof, a clutch hub 37cooperating with asecond clutchhub 38 formed as part of a pinion 39rotat-ably mounted on the countershaft 36 and ineshing'with a gear 4K0on the cam shaft 29. The hubs 3T and38 constitute the elements of aclutch through which the cam shaft 29, and consequently thc mechanismfor operating the ram 17, may be operatively connected with ordisconnected from the main or power shaft The clutch hub 37 is movable.longitudinally of the countershatt 36 to connect and disconnect theclutch by means of a clutch fork 41 termed at the endof one arm of a ltshap ed lever4e2 pivoted at 43 to a transverse frame member llconnecting the uprights 10, the other arm of said lever 42 beingconnected by a link 45 with a hand lever 1G p1voted at 47 to a lug l8 onone of the uprights 10 said hand lever 46 constituting means formanually operating the chit-cu iork or shitterdl to connect the clutch.y

T he clutch shli'tcr lever 42 is formed with an extension 49 providedwith a cam roller 50 extended into the path oi movement of a pair ofdogs 51 pivoted at 52 to one taco of the gear 40, said dogs having camprojections 53 for engaging the cam roller 50 and thereby operating theclutch shifter lever 1-2 to disconnect the clutch. The movement oi thedogs 51 011 their pivots 52 is limited by stop pins 5 1 and 55projecting from the face ot' the gear 10, the pins 54: being located inadvance of the pins 55 with reference to the direction of rotation ofsaid gear as indicated by the arrows on Figs. 2 and 3. The dogs 51 arenormally held in engagement with the pins 5% by means of springs 56connecting the same with. pins 57 also projecting from the face of saidgear, said dogs being however, adapted to yield against the tension ofthe springs 56 to the extent permitted by the stop pins f5. The dogs 51move in synchronism with the cam 32, and their positions on the gear 40,as determined by the stop pins 55, are such, with reference to said cam,that when the toggle 20 is fully straightened or fully broken, therebydetel-mining the limits Of movement of the ram 17 toward and from thebed 16, the cam projection 53 of one of said dogs will engage the camroller 50 and move the clutch shifter lever 42 on its pivot 43 todisconnect the clutch.

In operation, the hand lever 46 is moved on its pivot to connect theclutch, as shown in Fig. 1, thereby starting the press and causing amovement of the rain 1? to vard or from the bed 16, as the case may be.As shown in Fig. 2, the ram is moving away from the bed, and as itapproaches the limit of its movement in this direction the camprojection 53 on one of the dogs 51 is brougl'it into engagement withthe roller 50. Said dog thereupon yields about its pivot 52 and againstthe tension of the spring 56 until brought into engagement with its stoppin 55, as shown in Fig. 3 and in full lines in Fig. 4. At this time therain 17 has substantially reached the limit of its l'l'lOVOll'lOIit awayfrom the bed 16, and, the yielding movement of the dog 51 having beenarrested by the stop pin 55, the cam projection 53 thereon operates tomove the clutch shifter to disconnect the clutch and stop the machine.As soon as the cam roller 50 has been moved into the clutchdisconnecting position, the cam projection 53 on the dog 51 will besnapped past said roller by the spring 56, as shown in dotted lines Fig.4, thereby releasing said roller so as to permit the subsequent manualre-engagement ot the clutch when it is desired to start the machine. Itwill be understood that a similar stopping of the machine will be causedby the other dog 51 when the ram 17 reaches.

the limit of its movement toward the bed 16. In this manner the press isautomatically stopped when the ram has been moved completely away fromthe bed in order to permit the ready insertion or removal of the worlr,and is also stopped when the rain reaches the limit o t its movementtoward the bed to hold the work under Pl'QrSlllU, the stopping meansbeing, however, ol sol-h character as not to interfere with the manualstarting of the machine whenever desired.

Having thus described. my invent ion, claim:

1. In a power press, the combination with a bed and a ram, of mechanismincluding a rotary element and driving connections therefor for namingsaid ram toward and from said bed, means for discomiecting said drivingconnections, and dogs carried by said rotary element and having alimited yielding movement thereon for automatically operating saiddisconnecting means to arrest the movement of said ram when the latterreaches the limitoi its movement toward or from said bed.

2. In a power press, the combination with a bed and a ram, of mechanismincluding a rotary element and driving connections therefor for movingsaid rain toward and from said bed, a clutch for controlling saiddriving connections, a shifter for said clutch, a dog carried by saidrotary element and having a cam surface for engaging and operating saidclutch shifter to disengage said clutch, said dog being movably mountedon said rotary element, stops for limiting the movement of said dog, anda spring for normally holding said dog in engagement with one of saidstops.

3. In a powerpress, the combination with a bed and a rain, of mechanismfor moving said ram toward and from said bed, driving connections forsaid mechanism including a clutch, a shili'ter for said clutch, apivoted dog moving in syncbronism with said mechanism and adapted tooperate said clutch shifter to disengage said clutch when said ramreaches the limit of its movement, and a spring for snapping said dogpast said clutch shifter when said clutch has been disconnected topermit manual operation oi? said clutch shifter to ire-engage saidclutch.

4. In a power press, the combination with a bed, a ram, a shaft, andoperative connections between said shalt and ram :ii'or moving thelatter toward and from said bed, of a gear on said shaft, cooperatinggearing including a clutch for driving the same, a shifter for saidclutch, dogs carried by said gear and having cam surfaces adaptedrespectively to engage and operate said clutch shifter to disengage saidclutch when said ram reaches the limit 01 its movement in eitherdirection, said dogs being movably mounted on said gear, and s 'irinp'sfor snapping said dogs past said clutch slniter when said clutch hasbeen disconnected to permit Pill till) manual operation of said clutchshifter to reengage said clutch.

5. In a press, the combination of a movahle press element, a drivenshaft, mechanism operated therefrom for moving said element,

6. In a press, the combination of a movable press element, mechanismconnected to said element for moving the same, a driven shaft, a rotarycam carried thereby for shifting said mechanism, driving means for saiddriven shaft including a clutch, a lever for operating said clutch, adevice rotated from said driven shaft, and means for supporting saiddevice to permit movement of the de vice in syi'ichronism with said camto shift said lever and also to permit independent movement of saiddevice after shifting said lever.

In testimony whereof I aiiix my signature.

JASPER DERBY.

